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13 years ago. Rating: 3 | |
What Causes Eye Flashes?
Ordinarily, light entering your eye stimulates the retina. This produces an electrical impulse, which the optic nerve transmits to the brain. The brain then interprets this impulse as light or some type of image.
Doughnut FloatersAn unusually large floater called a "Weiss ring" represents a circular piece of condensed vitreous gel that is intimately attached around the optic nerve.
When this piece of vitreous separates from the optic nerve, many people will describe a circular, doughnut-shaped floater in their vision.
This ring sometimes will fold in half, creating a floater in the shape of a "J" or "C." — C.S.
If the retina is mechanically stimulated (physically touched), a similar electrical impulse is sent to the brain. This impulse is then interpreted as a "flicker" of light.
When the retina is tugged, torn or detached from the back of the eye, a flash or flicker of light commonly is noticed. Depending on the extent of the tear or detachment, these flashes of light might be short-lived or continue indefinitely until the retina is repaired.
Flashes (photopsia) also may occur after a blow to the head, often called "seeing stars."
Some people experience flashes of light that appear as jagged lines or "heat waves" in both eyes, often lasting 10-20 minutes. These types of flashes are usually caused by a spasm of blood vessels in the brain, which is called a migraine.
If a headache follows the flashes, it is called a migraine headache. However, jagged lines or "heat waves" can occur without a headache. In this case, the light flashes are called an ophthalmic migraine, or a migraine without a headache.
Photopsia also can be a symptom of digitalis toxicity, which can occur particularly in older people who take digitalis or related drugs for heart problems.
Other Conditions Associated With Eye Floaters and Flashes
Studies show that bleeding (vitreous hemorrhage) accompanying a PVD means exceptional traction has occurred, which increases the possibility of a retinal tear or detachment. Traction exerted on the retina during a PVD also can lead to development of conditions such as macular holes or puckers.
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13 years ago. Rating: 3 | |